An imaging system typically includes an input imaging device that generates image information, and an output imaging device that forms a visible representation of the image on an imaging element based on the image information. In a medical imaging system, for example, the input imaging device may include a diagnostic device, such as a magnetic resonance (MR), computed tomography (CT), conventional radiography (X-ray), or ultrasound device. Alternatively, the input imaging device may include a user interface device, such as a keypad, mouse, or trackball, which is also capable of generating medical image information. As a further alternative, the input imaging device may include an image archival workstation for retrieving archived images. In one embodiment, the output imaging device in a medical imaging system is a digital laser imager. In this embodiment, the laser imager exposes and develops the imaging element in response to the image information to form the visible representation of the image. Alternatively, the laser imager may combine multiple images into an "image page" and expose the imaging element to form a visible representation of the images. In another embodiment, the output imaging device is a softcopy output device such that the imaging element is a conventional display device for displaying the image information.
The image information generated by the input imaging device includes image data containing digital image values representative of the image, and imaging commands specifying operations to be performed by the laser imager. Each of the digital image values corresponds to one of a plurality of pixels in the original image, and represents an optical density associated with the respective pixel. In response to an imaging command, the laser imager converts the digital image values to generate laser drive values used to modulate the intensity of a scanning laser. The laser drive values are calculated to produce exposure levels, on the imaging element, necessary to reproduce the optical densities associated with the pixels of the original image when the media is developed, either by wet chemical processing or dry thermal processing.
Prior to imaging the media, an output imaging device may perform a number of additional operations on the image data to produce a variety of different format or appearance characteristics. For example, the output imaging device may apply numerous mathematical filters and transformations to the image data. In addition, the output imaging device may resize the image data in order to form a properly sized visible representation of the image. Furthermore, the image data may need to be rotated prior to imaging the media. The output imaging device performs image processing operations as a result of imaging commands from the input imaging device or due to other system variables such as the size of the imaging element or the resolution of the laser imager.
Because image processing is computationally intensive, many imaging systems incorporate specialized hardware designed to perform specific operations. The cost of specialized image-processing hardware, however, is extremely expensive and may prohibit incorporating such hardware into a laser imager. Other imaging systems incorporate sophisticated software algorithms that are optimized to reduce system requirements for image processing. These software algorithms, however, are inflexible and often require reprogramming in order to modify the image processing. Due to their lack of flexibility, conventional imaging systems are not well suited for asynchronous image processing requests received from the input imaging device. Furthermore, such imaging systems often require a complex operating system and virtual memory which are not well-suited for real-time applications and increase the overall cost of the medical imager.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a flexible image processing system capable of executing a variety of data operations without requiring specialized hardware. There is also a need for an image processing system that is easily configured in response to imaging requests received from a variety of input imaging devices.